'No such file or directory @ dir_s_mkdir - ' when running any gem install command

[slondr]

When I install ruby from asdf, or rbenv, or mise, version doesn't seem to matter (tried with ruby 3.2 and ruby 3.3), and run gem update --system, I get this without fail:

ERROR:  While executing gem ... (Errno::ENOENT)
    No such file or directory @ dir_s_mkdir - 
	/home/user/.local/share/mise/installs/ruby/3.2.4/lib/ruby/3.2.0/fileutils.rb:406:in `mkdir'
	/home/user/.local/share/mise/installs/ruby/3.2.4/lib/ruby/3.2.0/fileutils.rb:406:in `fu_mkdir'
	/home/user/.local/share/mise/installs/ruby/3.2.4/lib/ruby/3.2.0/fileutils.rb:384:in `block (2 levels) in mkdir_p'
	/home/user/.local/share/mise/installs/ruby/3.2.4/lib/ruby/3.2.0/fileutils.rb:382:in `reverse_each'
	/home/user/.local/share/mise/installs/ruby/3.2.4/lib/ruby/3.2.0/fileutils.rb:382:in `block in mkdir_p'
	/home/user/.local/share/mise/installs/ruby/3.2.4/lib/ruby/3.2.0/fileutils.rb:374:in `each'
	/home/user/.local/share/mise/installs/ruby/3.2.4/lib/ruby/3.2.0/fileutils.rb:374:in `mkdir_p'
	/home/user/.local/share/mise/installs/ruby/3.2.4/lib/ruby/3.2.0/rubygems/installer.rb:714:in `verify_gem_home'
	/home/user/.local/share/mise/installs/ruby/3.2.4/lib/ruby/3.2.0/rubygems/installer.rb:905:in `pre_install_checks'
	/home/user/.local/share/mise/installs/ruby/3.2.4/lib/ruby/3.2.0/rubygems/installer.rb:303:in `install'
	/home/user/.local/share/mise/installs/ruby/3.2.4/lib/ruby/3.2.0/rubygems/resolver/specification.rb:105:in `install'
	/home/user/.local/share/mise/installs/ruby/3.2.4/lib/ruby/3.2.0/rubygems/request_set.rb:195:in `block in install'
	/home/user/.local/share/mise/installs/ruby/3.2.4/lib/ruby/3.2.0/rubygems/request_set.rb:183:in `each'
	/home/user/.local/share/mise/installs/ruby/3.2.4/lib/ruby/3.2.0/rubygems/request_set.rb:183:in `install'
	/home/user/.local/share/mise/installs/ruby/3.2.4/lib/ruby/3.2.0/rubygems/dependency_installer.rb:253:in `install'
	/home/user/.local/share/mise/installs/ruby/3.2.4/lib/ruby/3.2.0/rubygems/commands/update_command.rb:247:in `update_gem'
	/home/user/.local/share/mise/installs/ruby/3.2.4/lib/ruby/3.2.0/rubygems/commands/update_command.rb:283:in `update_rubygems'
	/home/user/.local/share/mise/installs/ruby/3.2.4/lib/ruby/3.2.0/rubygems/commands/update_command.rb:99:in `execute'
	/home/user/.local/share/mise/installs/ruby/3.2.4/lib/ruby/3.2.0/rubygems/command.rb:328:in `invoke_with_build_args'
	/home/user/.local/share/mise/installs/ruby/3.2.4/lib/ruby/3.2.0/rubygems/command_manager.rb:253:in `invoke_command'
	/home/user/.local/share/mise/installs/ruby/3.2.4/lib/ruby/3.2.0/rubygems/command_manager.rb:193:in `process_args'
	/home/user/.local/share/mise/installs/ruby/3.2.4/lib/ruby/3.2.0/rubygems/command_manager.rb:151:in `run'
	/home/user/.local/share/mise/installs/ruby/3.2.4/lib/ruby/3.2.0/rubygems/gem_runner.rb:52:in `run'
	/home/user/.local/share/mise/installs/ruby/3.2/bin/gem:10:in `<main>'
Updating rubygems-update

The output here is from mise; the top level error message was identical with any installation method, only difference being the path to the rubygems directory.

Has anyone else seen this?

EDIT: I've also confirmed I get the same error when installing through nix (nix-shell -p ruby_3_3)

EDIT 2: I'm wondering if the fact that gem environment's GEM PATHS section has an empty entry could be related?

EDIT 3: It seems the Gem.paths blank entry is because Gem.paths.home is "".

[slondr]

Adding GEM_HOME=$(gem env user_gemhome) to my .zshrc file seems to have fixed the problem.

[deivid-rodriguez]

Interesting. I'm not sure what's going on. Can you investigate the result of Gem.default_dir?